Protocol for a remotely controlled videoconferencing robot

ABSTRACT

A robotic system that includes a robot and a remote station. The remote station can generate control commands that are transmitted to the robot through a broadband network. The control commands can be interpreted by the robot to induce action such as robot movement or focusing a robot camera. The robot can generate reporting commands that are transmitted to the remote station through the broadband network. The reporting commands can provide positional feedback or system reports on the robot.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 10/732,056, filed Dec. 9, 2003 now U.S. Pat. No. 7,813,836.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject matter disclosed generally relates to the field of robotics.

2. Background Information

There is a growing need to provide remote health care to patients thathave a variety of ailments ranging from Alzheimers to stress disorders.To minimize costs it is desirable to provide home care for suchpatients. Home care typically requires a periodic visit by a health careprovider such as a nurse or some type of assistant. Due to financialand/or staffing issues the health care provider may not be there whenthe patient needs some type of assistance. Additionally, existing staffmust be continuously trained, which can create a burden on trainingpersonnel. It would be desirable to provide a system that would allow ahealth care provider to remotely care for a patient without beingphysically present.

Robots have been used in a variety of applications ranging from remotecontrol of hazardous material to assisting in the performance ofsurgery. For example, U.S. Pat. No. 5,762,458 issued to Wang et al.discloses a system that allows a surgeon to perform minimally invasivemedical procedures through the use of robotically controlledinstruments. One of the robotic arms in the Wang system moves anendoscope which has a camera that allows a surgeon to view a surgicalarea of a patient.

Tele-robots such as hazardous waste handlers and bomb detectors maycontain a camera that allows the operator to view the remote site.Canadian Pat. No. 2289697 issued to Treviranus, et al. discloses ateleconferencing platform that has both a camera and a monitor. TheTreviranus patent also discloses embodiments with a mobile platform, anddifferent mechanisms for moving the camera and the monitor.

Publication Application No. US-2003-0050233-A1 discloses a remoterobotic system wherein a plurality of remote stations can control aplurality of robotic arms used to perform a minimally invasive medicalprocedure. Each remote station can receive a video image provided by theendoscope inserted into the patient. The remote stations are linked tothe robotic system by a dedicated communication link. The dedicated linkis required to insure communication quality during the performance ofremote surgical procedure. Dedicated links are not practical for arobotic product that can be used by a number of operators.

BRIEF SUMMARY OF THE INVENTION

A robotic system that includes a robot and a remote station thatcommunicate through a broadband network. Control commands can be sentfrom the remote station to the robot through the broadband network.Reporting commands can be sent to the remote station from the robot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a robotic system;

FIG. 2 is a schematic of an electrical system of a robot;

FIG. 3 is a further schematic of the electrical system of the robot;

FIG. 4 is side view of the robot;

FIG. 5 is a top perspective view of a holonomic platform of the robot;

FIG. 6 is a side perspective view of a roller assembly of the holonomicplatform;

FIG. 7 is a bottom perspective view showing a pedestal assembly of therobot;

FIG. 8 is a sectional view showing an actuator of the pedestal assembly;

FIG. 9 is a side view of a robot head.

DETAILED DESCRIPTION

Disclosed is a robotic system that includes a robot and a remotestation. The remote station can generate control commands that aretransmitted to the robot through a broadband network. The controlcommands can be interpreted by the robot to induce action such as robotmovement or focusing a robot camera. The robot can generate reportingcommands that are transmitted to the remote station through thebroadband network. The reporting commands can provide positionalfeedback or system reports on the robot.

Referring to the drawings more particularly by reference numbers, FIG. 1shows a robotic system 10. The robotic system 10 includes a robot 12, abase station 14 and a remote control station 16. The remote controlstation 16 may be coupled to the base station 14 through a network 18.By way of example, the network 18 may be either a packet switchednetwork such as the Internet, or a circuit switched network such has aPublic Switched Telephone Network (PSTN), or other broadband system. Thebase station 14 may be coupled to the network 18 by a modem 20 or otherbroadband network interface device.

The remote control station 16 may include a computer 22 that has amonitor 24, a camera 26, a microphone 28 and a speaker 30. The computer22 may also contain an input device 32 such as a joystick or a mouse.The control station 16 is typically located in a place that is remotefrom the robot 12. Although only one robot 12 and one station 16 areshown, it is to be understood that the system 10 may have a plurality ofrobots 12 and/or a plurality of remote stations that communicate throughthe broadband network. In general any number of robots 12 may becontrolled by any number of remote stations. For example, one remotestation 16 may be coupled to a plurality of robots 12, or one robot 12may be coupled to a plurality of remote stations 16.

The robot 12 includes a movement platform 34 that is attached to a robothousing 36. Also attached to the robot housing 36 are a camera 38, amonitor 40, a microphone(s) 42 and a speaker 44. The microphone 42 andspeaker 30 may create a stereophonic sound. The robot 12 may also havean antenna 45 that is wirelessly coupled to an antenna 46 of the basestation 14. The system 10 allows a user at the remote control station 16to move the robot 12 through the input device 32. The robot camera 38 iscoupled to the remote monitor 24 so that a user at the remote station 16can view a patient. Likewise, the robot monitor 40 is coupled to theremote camera 26 so that the patient can view the user. The microphones28 and 42, and speakers 30 and 44, allow for audible communicationbetween the patient and the user.

Each remote station computer 22 may operate Microsoft OS software andWINDOWS XP or other operating systems such as LINUX. The remote computer22 may also operate a video driver, a camera driver, an audio driver anda joystick driver. The video images may be transmitted and received withcompression software such as MPEG CODEC.

FIGS. 2 and 3 show an embodiment of the robot 12. The robot 12 mayinclude a high level control system 50 and a low level control system52. The high level control system 50 may include a processor 54 that isconnected to a bus 56. The bus is coupled to the camera 38 by aninput/output (I/O) port 58, and to the monitor 40 by a serial outputport 60 and a VGA driver 62. The monitor 40 may include a touchscreenfunction that allows the patient to enter input by touching the monitorscreen.

The speaker 44 is coupled to the bus 56 by a digital to analog converter64. The microphone 42 is coupled to the bus 56 by an analog to digitalconverter 66. The high level controller 50 may also contain randomaccess memory (RAM) device 68, a non-volatile RAM device 70 and a massstorage device 72 that are all coupled to the bus 62. The mass storagedevice 72 may contain medical files of the patient that can be accessedby the user at the remote control station 16. For example, the massstorage device 72 may contain a picture of the patient. The user,particularly a health care provider, can recall the old picture and makea side by side comparison on the monitor 24 with a present video imageof the patient provided by the camera 38. The robot antennae 45 may becoupled to a wireless transceiver 74. By way of example, the transceiver74 may transmit and receive information in accordance with IEEE 802.11b.

The controller 54 may operate with a LINUX OS operating system. Thecontroller 54 may also operate MS WINDOWS along with video, camera andaudio drivers for communication with the remote control station 16.Video information may be transceived using MPEG CODEC compressiontechniques. The software may allow the user to send e-mail to thepatient and vice versa, or allow the patient to access the Internet. Ingeneral the high level controller 50 operates to control thecommunication between the robot 12 and the remote control station 16.

The high level controller 50 may be linked to the low level controller52 by serial ports 76 and 78. The low level controller 52 includes aprocessor 80 that is coupled to a RAM device 82 and non-volatile RAMdevice 84 by a bus 86. The robot 12 contains a plurality of motors 88and motor encoders 90. The encoders 90 provide feedback informationregarding the output of the motors 88. The motors 88 can be coupled tothe bus 86 by a digital to analog converter 92 and a driver amplifier94. The encoders 90 can be coupled to the bus 86 by a decoder 96. Therobot 12 also has a number of proximity sensors 98 (see also FIG. 1).The position sensors 98 can be coupled to the bus 86 by a signalconditioning circuit 100 and an analog to digital converter 102.

The low level controller 52 runs software routines that mechanicallyactuate the robot 12. For example, the low level controller 52 providesinstructions to actuate the movement platform to move the robot 12. Thelow level controller 52 may receive movement instructions from the highlevel controller 50. The movement instructions may be received asmovement commands from the remote control station 16. Although twocontrollers are shown, it is to be understood that the robot 12 may haveone controller controlling the high and low level functions.

The various electrical devices of the robot 12 may be powered by abattery(ies) 104. The battery 104 may be recharged by a batteryrecharger station 106 (see also FIG. 1). The low level controller 52 mayinclude a battery control circuit 108 that senses the power level of thebattery 104. The low level controller 52 can sense when the power fallsbelow a threshold and then send a message to the high level controller50. The high level controller 50 may include a power management softwareroutine that causes the robot 12 to move so that the battery 104 iscoupled to the recharger 106 when the battery power falls below athreshold value. Alternatively, the user can direct the robot 12 to thebattery recharger 106. Additionally, the battery 104 may be replaced orthe robot 12 may be coupled to a wall power outlet by an electrical cord(not shown).

FIG. 4 shows an embodiment of the robot 12. The robot 12 may include aholonomic platform 110 that is attached to a robot housing 112. Theholonomic platform 110 provides three degrees of freedom to allow therobot 12 to move in any direction.

The robot 12 may have an pedestal assembly 114 that supports the camera38 and the monitor 40. The pedestal assembly 114 may have two degrees offreedom so that the camera 26 and monitor 24 can be swiveled and pivotedas indicated by the arrows.

As shown in FIG. 5 the holonomic platform 110 may include three rollerassemblies 120 that are mounted to a base plate 121. The rollerassemblies 120 are typically equally spaced about the platform 110 andallow for movement in any direction, although it is to be understoodthat the assemblies may not be equally spaced.

The robot housing 112 may include a bumper 122. The bumper 122 may becoupled to optical position sensors 123 that detect when the bumper 122has engaged an object. After engagement with the object the robot candetermine the direction of contact and prevent further movement into theobject.

FIG. 6 shows an embodiment of a roller assembly 120. Each assembly 120may include a drive ball 124 that is driven by a pair of transmissionrollers 126. The assembly 120 may include a retainer ring 128 and aplurality of bushings 130 that captures and allows the ball 124 torotate in an x and y direction but prevents movement in a z direction.The assembly also holds the ball under the transmission rollers 126.

The transmission rollers 126 are coupled to a motor assembly 132. Theassembly 132 corresponds to the motor 88 shown in FIG. 3. The motorassembly 132 includes an output pulley 134 attached to a motor 136. Theoutput pulley 134 is coupled to a pair of ball pulleys 138 by a drivebelt 140. The ball pulleys 138 are each attached to a transmissionbracket 142. The transmission rollers 126 are attached to thetransmission brackets 142.

Rotation of the output pulley 134 rotates the ball pulleys 138. Rotationof the ball pulleys 138 causes the transmission rollers 126 to rotateand spin the ball 124 through frictional forces. Spinning the ball 124will move the robot 12. The transmission rollers 126 are constructed toalways be in contact with the drive ball 124. The brackets 142 allow thetransmission rollers 126 to freely spin in a direction orthogonal to thedrive direction when one of the other roller assemblies 120 is drivingand moving the robot 12.

As shown in FIG. 7, the pedestal assembly 114 may include a motor 150that is coupled to a gear 152 by a belt 154. The gear 152 is attached toa shaft 156. The shaft 156 is attached to an arm 158 that is coupled tothe camera 38 and monitor 40 by a bracket 160. Activation of the motor150 rotates the gear 152 and sleeve 156, and causes the camera 38 andmonitor 40 to swivel (see also FIG. 4) as indicated by the arrows 4.

As shown in FIG. 8, the assembly 114 may further include a tilt motor162 within the arm 158 that can cause the monitor 40 and camera 38 topivot as indicated by the arrows 5. The tilt motor 162 may rotate a worm164 that rotates a worm gear 166. The pin 168 is rigidly attached toboth the worm gear 166 and the bracket 160 so that rotation of the gear166 pivots the camera 38 and the monitor 40. The camera 38 may alsoinclude a zoom feature to provide yet another degree of freedom for theoperator.

In operation, the robot 12 may be placed in a home or a facility whereone or more patients are to be monitored and/or assisted. The facilitymay be a hospital or a residential care facility. By way of example, therobot 12 may be placed in a home where a health care provider maymonitor and/or assist the patient. Likewise, a friend or family membermay communicate with the patient. The cameras and monitors at both therobot and remote control stations allow for teleconferencing between thepatient and the person at the remote station(s).

The robot 12 can be maneuvered through the home or facility bymanipulating the input device 32 at a remote station 16. The robot 10may be controlled by a number of different users. To accommodate forthis the robot may have an arbitration system. The arbitration systemmay be integrated into the operating system of the robot 12. Forexample, the arbitration technique may be embedded into the operatingsystem of the high-level controller 50.

By way of example, the users may be divided into classes that includethe robot itself, a local user, a caregiver, a doctor, a family member,or a service provider. The robot 12 may override input commands thatconflict with robot operation. For example, if the robot runs into awall, the system may ignore all additional commands to continue in thedirection of the wall. A local user is a person who is physicallypresent with the robot. The robot could have an input device that allowslocal operation. For example, the robot may incorporate a voicerecognition system that receives and interprets audible commands.

A caregiver is someone who remotely monitors the patient. A doctor is amedical professional who can remotely control the robot and also accessmedical files contained in the robot memory. The family and serviceusers remotely access the robot. The service user may service the systemsuch as by upgrading software, or setting operational parameters.

The robot 12 may operate in one of two different modes; an exclusivemode, or a sharing mode. In the exclusive mode only one user has accesscontrol of the robot. The exclusive mode may have a priority assigned toeach type of user. By way of example, the priority may be in order oflocal, doctor, caregiver, family and then service user. In the sharingmode two or more users may share access with the robot. For example, acaregiver may have access to the robot, the caregiver may then enter thesharing mode to allow a doctor to also access the robot. Both thecaregiver and the doctor can conduct a simultaneous tele-conference withthe patient.

The arbitration scheme may have one of four mechanisms; notification,timeouts, queue and call back. The notification mechanism may informeither a present user or a requesting user that another user has, orwants, access to the robot. The timeout mechanism gives certain types ofusers a prescribed amount of time to finish access to the robot. Thequeue mechanism is an orderly waiting list for access to the robot. Thecall back mechanism informs a user that the robot can be accessed. Byway of example, a family user may receive an e-mail message that therobot is free for usage. Tables I and II, show how the mechanismsresolve access request from the various users.

TABLE I Access Medical Command Software/Debug Set User Control RecordOverride Access Priority Robot No No Yes (1) No No Local No No Yes (2)No No Caregiver Yes Yes Yes (3) No No Doctor No Yes No No No Family NoNo No No No Service Yes No Yes Yes Yes

TABLE II Requesting User Local Caregiver Doctor Family Service CurrentLocal Not Allowed Warn current user of Warn current user of Warn currentuser of Warn current user of User pending user pending user pending userpending user Notify requesting Notify requesting user Notify requestinguser Notify requesting user that system is in that system is in use thatsystem is in use user that system is in use Set timeout = 5 m Settimeout = 5 m use Set timeout Call back No timeout Call back CaregiverWarn current user Not Allowed Warn current user of Warn current user ofWarn current user of of pending user. pending user pending user pendinguser Notify requesting Notify requesting user Notify requesting userNotify requesting user that system is that system is in use that systemis in use user that system is in in use. Set timeout = 5 m Set timeout =5 m use Release control Queue or callback No timeout Callback DoctorWarn current user Warn current user of Warn current user of Notifyrequesting user Warn current user of of pending user pending userpending user that system is in use pending user Notify requesting Notifyrequesting Notify requesting user No timeout Notify requesting user thatsystem is user that system is in that system is in use Queue or callbackuser that system is in in use use No timeout use Release control Settimeout = 5 m Callback No timeout Callback Family Warn current userNotify requesting Warn current user of Warn current user of Warn currentuser of of pending user user that system is in pending user pending userpending user Notify requesting use Notify requesting user Notifyrequesting user Notify requesting user that system is No timeout thatsystem is in use that system is in use user that system is in in use Putin queue or Set timeout = 1 m Set timeout = 5 m use Release Controlcallback Queue or callback No timeout Callback Service Warn current userNotify requesting Warn current user of Warn current user of Not Allowedof pending user user that system is in request pending user Notifyrequesting use Notify requesting user Notify requesting user user thatsystem is No timeout that system is in use that system is in use in useCallback No timeout No timeout No timeout Callback Queue or callback

The information transmitted between the station 16 and the robot 12 maybe encrypted. Additionally, the user may have to enter a password toenter the system 10. A selected robot is then given an electronic key bythe station 16. The robot 12 validates the key and returns another keyto the station 16. The keys are used to encrypt information transmittedin the session.

The robot 12 and remote station 16 transmit commands through thebroadband network 18. The commands can be generated by the user in avariety of ways. For example, commands to move the robot may begenerated by moving the joystick 32 (see FIG. 1). The commands arepreferably assembled into packets in accordance with TCP/IP protocol.Table III provides a list of control commands that are generated at theremote station and transmitted to the robot through the network.

TABLE III Control Commands Command Example Description drive drive 10.00.0 5.0 The drive command directs the robot to move at the specifiedvelocity (in cm/sec) in the (x, y) plane, and turn its facing at thespecified rate (degrees/sec). goodbye goodbye The goodbye commandterminates a user session and relinquishes control of the robotgotoHomePosition gotoHomePosition 1 The gotoHomePosition command movesthe head to a fixed “home” position (pan and tilt), and restores zoom todefault value. The index value can be 0, 1, or 2. The exact pan/tiltvalues for each index are specified in robot configuration files. headhead vel pan 5.0 tilt The head command controls the head motion. 10.0 Itcan send commands in two modes, identified by keyword: either positional(“pos”) or velocity (“vol”). In velocity mode, the pan and tilt valuesare desired velocities of the head on the pan and tilt axes, indegree/sec. A single command can include just the pan section, or justthe tilt section, or both. keepalive keepalive The keepalive commandcauses no action, but keeps the communication (socket) link open so thata session can continue. In scripts, it can be used to introduce delaytime into the action. odometry odometry 5 The odometry command enablesthe flow of odometry messages from the robot. The argument is the numberof times odometry is to be reported each second. A value of 0 turnsodometry off. reboot reboot The reboot command causes the robot computerto reboot immediately. The ongoing session is immediately broken off.restoreHeadPosition restoreHeadPosition The restoreHeadPositionfunctions like the gotoHomePosition command, but it homes the head to aposition previously saved with gotoHomePosition. saveHeadPositionsaveHeadPosition The saveHeadPosition command causes the robot to savethe current head position (pan and tilt) in a scratch location intemporary storage so that this position can be restored. Subsequentcalls to “restoreHeadPosition” will restore this saved position. Eachcall to saveHeadPosition overwrites any previously saved position.setCameraFocus setCameraFocus 100.0 The setCameraFocus command controlsfocus for the camera on the robot side. The value sent is passed “raw”to the video application running on the robot, which interprets itaccording to its own specification. setCameraZoom setCameraZoom 100.0The setCameraZoom command controls zoom for the camera on the robotside. The value sent is passed “raw” to the video application running onthe robot, which interprets it according to its own specification.shutdown Shutdown The shutdown command shuts down the robot and powersdown its computer. stop stop The stop command directs the robot to stopmoving immediately. It is assumed this will be as sudden a stop as themechanism can safely accommodate. timing Timing 3245629 500 The timingmessage is used to estimate message latency. It holds the UCT value(seconds + milliseconds) of the time the message was sent, as recordedon the sending machine. To do a valid test, you must compare results ineach direction (i.e., sending from machine A to machine B, then frommachine B to machine A) in order to account for differences in theclocks between the two machines. The robot records data internally toestimate average and maximum latency over the course of a session, whichit prints to log files. userTask userTask “Jane Doe” The userTaskcommand notifies the robot of “Remote Visit” the current user and task.It typically is sent once at the start of the session, although it canbe sent during a session if the user and/or task change. The robot usesthis information for record-keeping.

Table IV provides a list of reporting commands that are generated by therobot and transmitted to the remote station through the network.

TABLE IV Reporting Commands Command Example Description abnormalExitabnormalExit This message informs the user that the robot software hascrashed or otherwise exited abnormally. Te robot software catches top-level exceptions and generates this message if any such exceptionsoccur. bodyType bodyType 3 The bodyType message informs the stationwhich type body (using the numbering of the mechanical team) the currentrobot has. This allows the robot to be drawn correctly in the stationuser interface, and allows for any other necessary body-specificadjustments. driveEnabled driveEnabled true This message is sent at thestart of a session to indicate whether the drive system is operational.emergencyShutdown emergencyShutdown This message informs the stationthat the robot software has detected a possible “runaway” condition (anfailure causing the robot to move out of control) and is shutting theentire system down to prevent hazardous motion. odometry odometry 10 20340 The odometry command reports the current (x, y) position (cm) andbody orientation (degrees) of the robot, in the original coordinatespace of the robot at the start of the session. sensorGroup group_dataSensors on the robot are arranged into groups, each group of a singletype (bumps, range sensors, charge meter, etc.) The sensorGroup messageis sent once per group at the start of each session. It contains thenumber, type, locations, and any other relevant data for the sensors inthat group. The station assumes nothing about the equipment carried onthe robot; everything it knows about the sensors comes from thesensorGroup messages. sensorState groupName state data The sensorStatecommand reports the current state values for a specified group ofsensor. The syntax and interpretation for the state data is specific toeach group. This message is sent once for each group at each sensorevaluation (normally several times per second). systemError systemErrorThis message informs the station user of a driveController failure inone of the robot's subsystems. The error_type argument indicates whichsubsystem failed, including driveController, sensorController, headHome.systemInfo systemInfo wireless 45 This message allows regular reportingof information that falls outside the sensor system such as wirelesssignal strength. text text “This is some The text string sends a textstring from the text” robot to the station, where the string isdisplayed to the user. This message is used mainly for debugging.version version 1.6 This message identifies the software versioncurrently running on the robot. It is sent once at the start of thesession to allow the station to do any necessary backward compatibilityadjustments.

FIG. 9 shows a robot head 200 that can both pivot and spin the camera 38and the monitor 40. The robot head 200 can be similar to the robot 12but without the platform 110. The robot head 200 may have the samemechanisms and parts to both pivot the camera 38 and monitor 40 aboutthe pivot axis 4, and spin the camera 38 and monitor 40 about the spinaxis 5. The pivot axis may intersect the spin axis. Having a robot head200 that both pivots and spins provides a wide viewing area. The robothead 200 may be in the system either with or instead of the mobile robot12.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat this invention not be limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those ordinarily skilled in the art.

What is claimed is:
 1. A robot system that communicates through abroadband network, comprising: a robot that has a camera and a monitor,said robot generates two or more odometry reporting commands that aretransmitted to a remote station through the broadband network, each ofsaid odometry reporting commands reports a position of said robot; and,a remote station that has a camera and a monitor, said remote stationgenerates at least one odometry control command that is transmittedthrough the broadband network to said robot, said odometry controlcommand specifies a frequency with which said two or more odometryreporting commands are reported by said robot, and receives the odometryreporting commands from said robot.
 2. A method for controlling a robotthrough a broadband network, comprising: generating at least oneodometry control command at a remote station that has a camera and amonitor; transmitting the odometry control command through a broadbandnetwork; receiving the odometry control command at a robot that has acamera and a monitor, wherein said odometry control command specifies afrequency at which odometry reporting commands are reported by saidrobot; generating two or more odometry reporting commands at the robotin accordance with said odometry control command, each of said odometryreporting commands reports a position of said robot; transmitting theodometry reporting commands through the broadband network; and,receiving the odometry reporting commands at the remote station.